Answer: Wildflower meadows are not maintenance-free although that is the impression that many people have. It's important to pull grass as soon as you see it, before it spreads or goes to seed. Also, be sure that the mix you plant is 100 percent flower seed, with no grass fillers.
Some grasses spread by runners; tilling can chop up the runners, actually creating more plants. Before tilling, cover the area with a thick mulch of newspaper or cardboard to deprive the runners of light, and they should die in a month or so. Then till the area, water it, wait two weeks, and till again to remove germinating weed seeds. Then plant the wildflower seed.
Generally, it can take several years to establish a wildflower area because some plants will return more vigorously than others, just as in nature. You need to (1) keep after the weeds, and (2) thin out the more vigorous wildflowers that you have too many of, and (3) continue to resow for variety. Follow the directions on the seed package; most meadows should be mown yearly to help disperse the annual seed.
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